A man accused of murdering his father near Clayton last week appeared in court Tuesday and was set to be arraigned next week on murder and assault charges.

Matthew Wester, 22, was charged today with murder and assault by force likely to cause great bodily injury for the death of his father, 61-year-old Richard Wester, on Friday.

At about 11 a.m. that day, sheriff's deputies were called to the father's home in the 400 block of Meadow View Lane, where they found him unconscious and not breathing, according to sheriff's spokesman Jimmy Lee.

The results of an autopsy conducted Monday show there was blood in Wester's chest from multiple rib fractures at the time of his death and that he ultimately died from chest injuries, Lee said.

Lee declined to elaborate about how Wester was killed or whether a weapon was used.

An investigation quickly led detectives to Matthew Wester, who was arrested on suspicion of murder.

He was being held at county jail in Martinez Tuesday on $1.08 million bail.

Wester appeared behind a partition in a Martinez courtroom that day wearing a yellow county jail jumpsuit.

He looked down as a judge scheduled his arraignment for next Tuesday at 1:30 p.m.

According to a restraining order Richard Wester filed against his son in 2010, Matthew Wester, whom he said suffers from Asperger's syndrome and lives in a group home, has a history of anger problems and violence and described the young man as being "prone to rage."

In the documents, Wester described an incident in March 2010 in which his son came to his house and became angry when he was told he could not live there.

He said his son "spit in my face, punched and kicked me, destroyed furniture, waved a knife, stole from me and broke into my house."

He said in the restraining order that the violent outburst followed similar flare-ups over the past two years, but that the incidents were "increasing in frequency and intensity."